A seat apparatus is known from, e.g., JP 09-175243 A wherein a cushion is formed using an airspring, a seat is manually or automatically deflated, and a space needed to facilitate escape is formed.
Further, a vehicle seat arranged to retract when a vehicle is involved in a head-on collision is disclosed in JP 2007-168703 A.
FIG. 10 hereof illustrates the seat apparatus of JP 09-175243 A. As shown in FIG. 10, the vehicle seat apparatus 201 comprises a cushion 202 formed of an airspring 203; and a wire cable 204 that opens a stopcock 205 when a vehicle is involved in a collision and a vehicle body panel collapses, so that the weight of a vehicle occupant or another force causes air to be removed from a discharge opening 206 to cause the airspring 203 to deflate, thereby providing a space needed to rescue the vehicle occupant
However, the air pressure of the airspring 203 changes in the seat apparatus 201 due to atmospheric pressure or other environmental conditions; therefore, the seat can become less comfortable, and the air pressure can be difficult to control. A control component for opening the stopcock 205 must also be added, making the structure more complex.
FIG. 11 illustrates the vehicle seat of JP 2007-168703 A. As shown in FIG. 11, the vehicle seat apparatus 220 includes a controller 222 that, when a vehicle is involved in a head-on collision, causes, on the basis of information from an acceleration sensor 221, drive means 223 to retract a sliding piece 224 to the state shown in the Figure, with the result that a locking part 225 is released from the seat. When a load is applied to the seat in a rearward direction, as shown by arrow a1, the vehicle seat 220 automatically retracts to allow the vehicle occupant to easily escape.
However, since the seat is caused to retract automatically when a load is applied to the vehicle seat 221 in a rearward direction (in the direction shown by arrow a1), a problem is presented in vehicles having a rear seat behind the seat 221, because a passenger occupying the rear seat will serve as a source of interference. Furthermore, a rail that guides the retraction of the seat may deform in the event of a head-on collision.